Supermarket sales were growing at their fastest rate since June 2014 over the past three months as inflation started to bump up prices for key items such as tea, butter and fish.
According to data from Kantar Worldpanel, supermarket sales grew by 2.3 per cent year-on-year for the 12 weeks ending 26 February.
Kantar said price rises on grocery items were "still far from universal" but that prices on butter, tea and fish had all gone up by more than five per cent in the last three months. The UK's largest dairy company, Arla Foods, which makes Lurpak and Anchor butter, recently said it had increased its products' prices for supermarkets.
Tesco managed to boost its sales for the sixth period in a row, but the UK's biggest supermarket still lost market share, with its slice of the grocery market falling by 0.5 percentage points to 27.9 per cent. The grocer's share price was down 1.5 per cent in morning trading.
Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: “While consumers may be starting to feel a very slight pinch, increased inflation has led to overall market growth. Simultaneously, combined sales at the UK’s four largest supermarkets increased by 0.5 per cent year-on-year.
"This is a timely reminder that despite the huge interest in the discounters during recent years the big four remain a force to be reckoned with: they still hold just over 70 per cent of the market, with almost 99 per cent of the population shopping in a Tesco, Sainsbury’s, Asda or Morrisons during the latest quarter.”